There are many resources that an interested reader can refer to. For basic analog VLSI circuits and systems Carver Mead's book, Analog VLSI and Neural Systems [Mead 89b], provides an excellent systematic overview on the design of neuromorphic systems. There are several other published books which can be of some help, for example [Ismail and Fiez 94, Mead and Ismail 89, Sheu and Choi 95, Mahowald 94b]. There is also a paper collection from IEEE Press edited by C. Koch and H. Li [Koch and Li 94] which is an easy reference to publications on many vision chips.
Unfortunately, there is still no properly edited book on vision chips to cover various aspects in the design. Although some books on analog VLSI may contain some information, these information have come as examples for neural systems implemented in VLSI. They lack a systematic approach to the design of vision chips.
For on line materials, one of the best locations to check is the WWW and FTP site at Caltech addressed at ``www.pcmp.caltech.edu'' and ``ftp.pcmp.caltech.edu'', respectively. In particular Tobi Delbruck's home page has many articles, reports, and his resourceful PhD thesis covering various aspects of the design of vision chips, specially on the design and characterization of photodetectors and photocircuits.
In the ``html'' format of this report, the home page of each vision
chip has links to the home page of the designers of the chip, to
postscript papers, and to other online material.
The reader is highly encouraged to follow those links.
Also there are links to the home pages of the groups and researchers
working in this area which can be accessed in the main home page of this
document in
http://www.eleceng.adelaide.edu.au/Groups/GAAS/Bugeye/visionchips/''.
In the bibliography I have tried to include as many references to one work as possible. This is specially helpful when there is not access to a particular publication, but alternative sources in which the work has been presented can be accessed.